package model

import "sync"

// Experiments are optional functionality that can be enabled/disabled by an application either completely or individually.
// examples of experiments include File Sharing, Profile Images and Groups.
type Experiments struct {
	enabled     bool
	experiments map[string]bool
	lock        sync.Mutex
}

// InitExperiments encapsulates a set of experiments separate from their storage in GlobalSettings.
func InitExperiments(enabled bool, experiments map[string]bool) Experiments {
	return Experiments{
		enabled:     enabled,
		experiments: experiments,
	}
}

// IsEnabled is a convenience function that takes in an experiment and returns true if it is enabled. Experiments
// are only enabled if both global experiments are turned on and if the specific experiment is also turned on.
// The one exception to this is experiments that have been promoted to default functionality which may be turned on
// even if experiments turned off globally. These experiments are defined by DefaultEnabledFunctionality.
func (e *Experiments) IsEnabled(experiment string) bool {
	if !e.enabled {
		// todo handle default-enabled functionality
		return false
	}

	// go will sometimes panic if we do not lock this read-only map...
	e.lock.Lock()
	defer e.lock.Unlock()
	enabled, exists := e.experiments[experiment]
	if !exists {
		return false
	}
	return enabled
}